Traditional, or open, surgical techniques may require a surgeon to make large incisions in a patient's body in order to access a tissue treatment region, or surgical site. In some instances, these large incisions may prolong the recovery time of and/or increase the scarring to the patient. As a result, minimally invasive surgical techniques are becoming more preferred among surgeons and patients owing to the reduced size of the incisions required for various procedures. In some circumstances, minimally invasive surgical techniques may reduce the possibility that the patient will suffer undesirable post-surgical conditions, such as scarring and/or infections, for example. Further, such minimally invasive techniques can allow the patient to recover more rapidly as compared to traditional surgical procedures.
Endoscopy is one minimally invasive surgical technique which allows a surgeon to view and evaluate a surgical site by inserting at least one cannula, or trocar, into the patient's body through a natural opening in the body and/or through a relatively small incision. In use, an endoscope can be inserted into, or through, the trocar so that the surgeon can observe the surgical site. In various embodiments, the endoscope may include a flexible or rigid shaft, a camera and/or other suitable optical device, and a handle portion. In at least one embodiment, the optical device can be located on a first, or distal, end of the shaft and the handle portion can be located on a second, or proximal, end of the shaft. In various embodiments, the endoscope may also be configured to assist a surgeon in taking biopsies, retrieving foreign objects, and introducing surgical instruments into the surgical site.
Laparoscopic surgery is another minimally invasive surgical technique where procedures in the abdominal or pelvic cavities can be performed through small incisions in the patient's body. A key element of laparoscopic surgery is the use of a laparoscope which typically includes a telescopic lens system that can be connected to a video camera. In various embodiments, a laparoscope can further include a fiber optic system connected to a halogen or xenon light source, for example, in order to illuminate the surgical site. In various laparoscopic, and/or endoscopic, surgical procedures, a body cavity of a patient, such as the abdominal cavity, for example, can be insufflated with carbon dioxide gas, for example, in order to create a temporary working space for the surgeon. In such procedures, a cavity wall can be elevated above the organs within the cavity by the carbon dioxide gas. Carbon dioxide gas is usually used for insufflation because it can be easily absorbed and removed by the body.
In at least one minimally invasive surgical procedure, an endoscope and/or laparoscope can be inserted through a natural opening of a patient to allow a surgeon to access a surgical site. Such procedures are generally referred to as Nature Orifice Transluminal Endoscopic Surgery or (NOTES)™ and can be utilized to treat tissue while reducing the number of incisions, and external scars, to a patient's body. In various NOTES™ procedures, for example, an endoscope can include at least one working channel defined therein, which can be used to allow the surgeon to insert a surgical instrument therethrough in order to access the surgical site.
Minimally invasive surgical procedures may employ electrical ablation therapy for the treatment of undesirable tissue such as diseased tissue, cancer, malignant and benign tumors, masses, lesions, and other abnormal tissue growths in a tissue treatment region. While conventional apparatuses, systems, and methods for the electrical ablation of undesirable tissue are effective, one drawback with conventional electrical ablation treatment is the resulting permanent damage that may occur to the healthy tissue surrounding the abnormal tissue due primarily to the detrimental thermal effects resulting from exposing the tissue to thermal energy generated by the electrical ablation device. This may be particularly true when exposing the tissue to electric potentials sufficient to cause cell necrosis using high temperature thermal therapies including focused ultrasound ablation, radiofrequency (RF) ablation, or interstitial laser coagulation. Other techniques for tissue ablation include chemical ablation, in which chemical agents are injected into the undesirable tissue to cause ablation as well as surgical excision, cryotherapy, radiation, photodynamic therapy, Moh's micrographic surgery, topical treatments with 5-fluorouracil, and/or laser ablation. Other drawbacks of conventional thermal, chemical, and other ablation therapy are cost, length of recovery, and the pain inflicted on the patient.
Conventional thermal, chemical, and other ablation techniques have been employed for the treatment of a variety of undesirable tissue. Thermal and chemical ablation techniques have been used for the treatment of varicose veins resulting from reflux disease of the greater saphenous vein (GSV), in which the varicose vein is stripped and then is exposed to either chemical or thermal ablation. Other techniques for the treatment of undesirable tissue are more radical. Prostate cancer, for example, may be removed using a prostatectomy, in which the entire or part of prostate gland and surrounding lymph nodes are surgically removed. Like most other forms of cancer, radiation therapy may be used in conjunction with or as an alternate method for the treatment of prostate cancer. Another thermal ablation technique for the treatment of prostate cancer is RF interstitial tumor ablation (RITA) via trans-rectal ultrasound guidance. While these conventional methods for the treatment of prostate cancer are effective, they are not preferred by many surgeons and may result in detrimental thermal effects to healthy tissue surrounding the prostate. Similar thermal ablation techniques may be used for the treatment of basal cell carcinoma (BCC) tissue, a slowly growing cutaneous malignancy derived from the rapidly proliferating basal layer of the epidermis. BCC tissue in tumors ranging in size from about 5 mm to about 40 mm may be thermally ablated with a pulsed carbon dioxide laser. Nevertheless, carbon dioxide laser ablation is a thermal treatment method and may cause permanent damage to healthy tissue surrounding the BCC tissue. Furthermore, this technique requires costly capital investment in carbon dioxide laser equipment.
Undesirable tissue growing inside a body lumen such as the esophagus, large bowel, or in cavities formed in solid tissue such as the breast, for example, can be difficult to destroy using conventional ablation techniques. Surgical removal of undesirable tissue, such as a malignant or benign tumor, from the breast is likely to leave a cavity. Surgical resection of residual intralumenal tissue may remove only a portion of the undesirable tissue cells within a certain margin of healthy tissue. Accordingly, some undesirable tissue is likely to remain within the wall of the cavity due to the limitation of conventional ablation instrument configurations, which may be effective for treating line-of-sight regions of tissue, but may be less effective for treating the residual undesirable tissue.
Accordingly, there remains a need for improved electrical ablation apparatuses, systems, and methods for the treatment of undesirable tissue found in diseased tissue, cancer, malignant and benign tumors, masses, lesions, and other abnormal tissue growths. There remains a need for minimally invasive treatment of undesirable tissue through the use of irreversible electroporation (IRE) ablation techniques without causing the detrimental thermal effects of conventional thermal ablation techniques.
The foregoing discussion is intended only to illustrate various aspects of the related art in the field of the invention at the time, and should not be taken as a disavowal of claim scope.